Wavefunction of Macroscopic Objects

[StevieTNZ]

1) Macroscopic objects have their own wavefunction, right? Would this wavefunction include physical attributes that would contain possibilities for certain features that macroscopic objects have (say the macroscopic object is a bed – the wavefunction would have possibilities for all the different colours the bed can be such as blue, black, green (though admittedly I haven’t seen a green bed before!)). So generally what we see as macroscopic objects, everything about those objects is merely possibilities in a wavefunction, if that makes sense.

2) If the entire universe is represented by a wavefunction, would that wavefunction be the sum of all the wavefunctions of atoms, macroscopic objects etc (i.e. an atoms wavefunction would make up part of the universe's wavefunction)?

 

[Matterwave]

1) Macroscopic objects tend to be highly incoherent, and so we can't really construct a nice wave-function for them because we cannot obtain the relative phase information between particles in that object. In other words, because macroscopic objects tend to be in mixed states rather than pure states, we cannot describe them using a state-vector (or a ket). The best we can do is construct some sort of density operator. There are some exceptions to this, e.g. lasers, superconducitivity, and superfluidity.